Semitendinosus
Picture:
external image hamstring_group-148E129F4FC6ACD82D7.jpg
Origin: ischial tuberosity
Insertion: medial aspect of upper tibial shaft
Action: extends thigh and flexes knee / medially rotates leg with semimembranosus
Two joint muscle.

Strengthening: The semitendinosus muscle can be strengthened with knee curls with either added weight or resistance bands. A more advanced strengthening technique for the semitendinosus muscle is the Nordic curl. A partner will hold the calves of the individuals as the individual stretches from a kneeling position to the floor and returns to the kneeling position.

Injury: Some critical injuries to this muscle include a pulled or torn hamstring (sprain/strain), bruised ischial tuberosity, deep vascular thrombosis, and cauda equina syndrome.

Rehabilitation: Isometric holds and varied hamstring curls are possible rehabilitation methods for injuries to the semitendinosus muscle. Resistance bands or weight can be added, but caution should be taken to not further injure the muscle while rehab is completed. Also, knee sleeves with compression around the knee joint have been found to reduce pain in the hamstring area.

Interesting/Fun Fact: The semitendinosus is one of the most frequent injuries in sports, 42% of athletes do not recover after non operative treatment.